DE3129649A1 - ELECTRONIC CYLINDER MANUFACTURING PROCESS - Google Patents

Description

Patent attorneys

Dipl.-Ing. Hane-Jürgen Müller DipL-Chem. Dr. Gerhard Scbupfner Dipl.-Ing. Hans -Peter Gauger Luclle-Grahn-Str. 38 - D 8000 Munich 80

TOPPMT PRDITITiG CO., LTD

5-1, 1-chome,

Taito, Taito-ku

Tokyo

Japan

Jilektronischo's cylinder manufacturing process

Electronic cylinder manufacturing process

The invention relates to a method for electronic Production of cylinders with which the same patterns are repeatedly arranged on a web to be printed are printable.

Pattern that z. B. printed on a component such as a decorative panel, on flooring material, wallpaper or printed fabric are mostly endless patterns, with the same patterns arranged continuously in a certain direction are, or multiple patterns, the same pattern are arranged repetitively at a certain distance, or composite or mixed patterns, with the same pattern can be printed by a combination of both of the foregoing arrangements. For example, a grain is through a Composite or composite pattern created.

A known device for electronic cylinder production with the aforementioned endless and / or multiple pattern is z. As in US Patent Nos A- 057,838 and i specified \ 013 (HELIO-KLISHOGRAPH K-200, manufactured by Dr. Ing R. Hell GmbH;. Briefly below HELIO device called a "). If the HELIO device produces an endless and a multiple pattern, it is necessary to use a

certain form of original to be provided, the top to bottom below .and from right to left has a continuous pattern, and also sections of the pattern drawn on the upper and lower sides with an equal degree of density, and sections of the pattern on the right and left are also using drawn with the same degree of density. Usually such an original is produced photographically. The original will stretched on the outer jacket of a reading cylinder. A Pattern is engraved on a printing cylinder with a density signal generated by a reading head. If in this If the longitudinal section of the original is engraved on exactly one circumference of the printing cylinder, an endless pattern is created generated. When a pattern printed on the original is repeated in the axial direction of the impression cylinder is engraved, a multiple pattern is produced.

However, there are significant difficulties in making an original with a continuous pattern from top to bottom and from right to left, further including the sections of the pattern at the top and the lower side and the sections of the pattern on the right and left side have the same degree of density to have. Even if there is a density difference between the density with which e.g. B. drawn the pattern on the top is, and the density with which the pattern is drawn on the underside is so low that it is even with is not detectable with a densitometer, the difference in density occurs clearly at the junction of the respective Pattern on a printed web. As a result, defective cylinder manufacture, i.e. H. a Failure to make the original, often only after attempting printing with a such original noted. So far it was

It is necessary to produce a printing cylinder again after a correction process or an original or to re-produce a printing cylinder created with this. In each case, the work mentioned was very time consuming and costly.

The task of the invention is to create a procedure for the electronic production of a printing cylinder or a printing roller on which an overall pattern, consisting of an arrangement of the same components, is engraved without being at the seams density differences occur in the corresponding sample components.

To solve the aforementioned problem is according to the invention an electronic cylinder manufacturing process provided that the following procedural steps comprises: scanning an original print, performing photoelectric conversion and generation of a signal indicative of the density of the original print; and correcting a pattern indicative of the density of the pattern printed on one side of the original Signal by a signal that represents the density of that printed on the opposite side of the original Designated pattern, the correction speed depending on a distance from the edge of the original of the pattern whose density is to be corrected changes.

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The original 1 laid out as above is fitted on the pick-up cylinder. During the reading cylinder rotates, the reading head is moved from left to right over the original, so that the density of the original pattern indicative signal is generated.

A density signal generated in this way is scanned upon receipt of a clock signal which occurs synchronously with the rotation of the reading cylinder. The sampled signal is subjected to an analog-digital conversion so that density information D (see FIG. 2) corresponding to the pattern of the original according to FIG. 1 is obtained. The number of mesh points on the printing cylinder per circumference is determined by the outer diameter and the screen grid (the density of the mesh points). The number of circumferentials of the screen points is equal to the number N scanning points per scanning line in the FB section of FIG. 1. In the exemplary embodiment explained, the number η of scanning points = 200 is selected. Therefore, a signal indicative of the density of the FC section is scanned at (N + 200) scanning points per scanning line. The number K of scanning lines of the LR section is e.g. B. determined by the width of a main pattern and the screen grid on the printing cylinder. In the above embodiment, the number k of scanning lines of the RS section = 20O ₄ Assume that density information is counted at an intersection of an X-th line counted from the left side L of the original 1 and a Y-th point from the front side F of the original 1, denoted by D (X, Y) (X and Y are natural numbers, it being assumed that K + k and ΙέΥέ

A longitudinal density correction is carried out by adding density information corresponding to the section FG due to density information corresponding to the extended section BC is corrected. Density information of the extended

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Section BC is gradually converted into density information of the corresponding FG section, whereby the corrected density information D ^{1 of} the FG section is obtained. Assuming that η = 200, the density information of the FG portion in the longitudinal direction is corrected by the following operation:

If Y is an even number, then is

ν ί? ηπ γ

D '(X, Y) = D (X, Y) -jLq + D (X, Y + N)

If Y is an odd number, then D '(X, Y) = D' (X, Y + 1)

The above equations are used in the operation of a first group. The information D ¹ relating to the longitudinally corrected density of the GB section is derived directly from the original information D relating to the density of the GB section. The information on the density of the FB portion is corrected lengthwise because there is hardly any difference between the density value of the front side F of the original and that of the back side B.

The density information of the LM section is corrected crosswise due to the density information of the corresponding extended RS section. The information D "pertaining to the cross-corrected density of the LM portion is obtained by gradually converting information on the density of the corresponding RS section in information on the density of the LM section.

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Assuming that k = 200, the density information of the LM section corrected in the transverse direction by the following operation:

If X is an even number, then:

D- (X, Y) = D (X, Y) - ^ ₊ D (X ₊ K, Y) ·. If X is an odd number, then:

D "(X, Y) = D" (X + 1, Y)
(1 ^ X t 200).

The above equations are used for the operation of a second group. Information D "regarding the cross-corrected density of the MR section is obtained directly from the original information D relating to the density of the MR section derived. Information regarding the density of the LR section is cross-corrected because between the degree of density of the left side L of the original and that of its right side R is no difference.

Each of the longitudinal and transverse density corrections can be made before the other. Correct density correction however, it can be achieved by sequentially performing both types of density correction will. As will be explained below, the longitudinal density correction is carried out before the transverse density correction.

Information regarding the corrected density of the front side, d. H. of the FG section, the original and information concerning the corrected density of the left side, d. H. of the LM section, the original are with

D " ¹ (cf. FIG. 3). A screen pattern (cf. FIG. K) is preferably engraved on a printing cylinder 50 from the information D" ^{1 in} such a way that between the front side F and the rear side B and between the right side R and the left side L an exact alignment is ensured.

According to Fig. 4, it is not necessary to engrave a pattern on the leftmost (first) main pattern portion by applying the aforementioned information D " ¹ relating to the transversely corrected density. In the embodiment of the invention, a cough is applied to the first Main pattern section is engraved using only information D ¹ relating to the length corrected density, as will be explained.

The operation of the electronic cylinder manufacturing device will now be explained with reference to FIG. An original 1 for an endless and multiple pattern is placed on the circumferential surface of a reading cylinder 11 applied. While the reading cylinder is rotating, a reading head 20 is moved. Reflections from the original 1 are converted photoelectrically by one photoelectric converter of the reading head 20 so that a density signal is obtained. A density signal generated in this way is fed to an analog-to-digital converter 21, where sampling and a 10-bit analog-to-digital conversion are carried out will.

10-bit serial digital density signals thus generated are a serial-parallel converter 22 is supplied and converted into parallel digital signals. These parallel digital signals are also converted into 8-bit density signals by a 10-bit / S-bit converter 23 implemented with 256 degrees of density.

Then the density signal is passed to a tone curve converter 26 supplied, the signals if necessary to carry out a z. B. Negative-positive conversion and a gradation correction processed. The processed Signals are fed to a computer. Channel selectors 25, 27, each having 1-8 channels, will be operated with mutual locking so that several reading heads 20 and several engraving heads can be operated in parallel are to simultaneously create a plurality of identical patterns which are arranged repetitively in the transverse direction to engrave on a printing cylinder. The arrangement explained above is already from the HELIO facility known and is therefore not explained.

A density signal supplied by the channel selector 27 is sent to a central processing unit (ZE) 35 through an input register 30 and an input interface 31 are supplied. The ZE 35 carries out a density correction to compensate for differences in density at longitudinal and / or transverse seams of adjacent patterns.

The ZE 35 is connected to a keyboard 33. Information on the diameter of a printing cylinder 50, the width of each of the multiple patterns and the screen raster of the printing cylinder 50 are entered via the keyboard 33. N scanning points per circumferential line of the printing cylinder 50 and K lines from which each pattern is formed are calculated from the information entered from the keyboard 33. The counted information is fed to a computer. The ZE 35 is connected to a memory 34 which is used for the cross correction. In the embodiment shown, the memory 34, which must have a large storage capacity, is a magnetic disk memory. The memory 34 stores information D ¹ relating to the longitudinally corrected density of the RS section,

Information D ¹ relating to the longitudinally corrected density of the LM section and information D "'relating to the longitudinally and transversely corrected density of the LM section.

The ZE 35 causes signals that the longitudinal and / or denote cross-corrected densities, in a core memory 40 for each line through an output interface 36 and an output register 37 of the computer. A density signal output from the computer denotes (N + n) density information per line. Consequently the core memory 40 stores (N + η) density information per line. However, if only a number N of the previous density information from the core memory 40 is read out, then a number η of the subsequent density information items, which have become unnecessary, is omitted is.

Density signals stored in the core memory 40 are at Receipt of an address signal that is synchronous with the rotation of the printing cylinder 50 occurs, read out. The selected ones Density signals are converted into analog signals by a digital-to-analog converter 42. After that will be engraved on the printing cylinder 50 screen pattern by means of an engraving head 43, so that finally a printing cylinder is generated.

Figure 6 is a flow diagram of the computer employed with the invention. Section 60 of the flowchart relates refers to the steps of previously scanning the RS portion of the original for transverse density correction and storing data relating to the longitudinally corrected density of the RS section in the disk memory 34th section 70 of the flowchart relates to longitudinal density correction, i. H. Line by line registered mail of the density signals generated by scanning the LR section during the first engraving into the core memory 40

and writing in line by line those generated by scanning the MR section during the subsequent engraving Density signals. Section 80 of the flow chart relates to transverse density correction.

A subroutine 90 relates to the steps of supplying a density signal to the computer and reading out the Density signal from the computer, d. H. the supply of the density signal for each line to the computer and the supply a density correction signal to core memory 40 for each line.

In step 61, when the storage of the transversely elongated patterns begins, the reading head 20 is set on the right side R of the original 1. In step 62, density signals are supplied for each line (corresponding to a number (N + n) of density data). In step 63 a longitudinal correction takes place (for each sampling point). In step 64, it is decided whether η (= 200) previous density data has been longitudinally corrected for each line. In step 65, signals representing the corrected densities for each line (corresponding to a number (N + n) of data) are stored in the disk memory 34. In step 66 , the operation returns to step 62. In step 62, density signals for one line are supplied in the second operation cycle. Then the same steps as in the first operation cycle are repeated for k (= 200) lines. As a result, data relating to the longitudinally corrected density of the RS section is stored in the disk memory 34. Step 66 is followed by step 71, in which the printing of a main pattern, as opposed to the additional elongated coughs, begins. In step 71, at the start of printing, the reading head 20 is disposed on the left side L of the original 1. In step 72 density signals for each

Line fed. Signals indicating corrected densities for each line are written in the core memory AO. In step 73, a longitudinal density correction is carried out for each line. In steps lh and 75, data relating to the longitudinally corrected density are shifted in the data memory of the computer. The information shift takes place for the reason that the point in time at which a light signal is output from the computer is delayed, whereby a signal indicating a corrected density is sent out simultaneously with the supply of a light signal from the computer. With the above arrangement, a computer can be additionally provided with minor modifications to the conventional electronic cylinder positioning device. In step 76, signals which represent the densities of k (= 200) scanning lines (that is to say the longitudinally corrected densities of the LM section) are stored in the disk memory 34.

In step 77, it is decided whether the engraving of the main pattern is finished. The scanning is carried out by the left side L to right side R of the original 1 for longitudinal density correction, thereby producing a desired main pattern 51 is engraved on the surface of the printing cylinder 50, and thereby data relating to the longitudinally corrected The density of the LM section is stored in the disk memory 34- ■. As mentioned above, the first Engraving of a master pattern on the impression cylinder 50 is finished. At step 77, in which the first print of the Main pattern has been completed, step 81 follows. Originally, step 81 is followed by step 82. In step 82 takes place a transverse density correction of data on the longitudinally corrected density of the sections LM and RS, the are stored in disk storage 34. In step 83

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data relating to the longitudinally and transversely corrected density for k (= 200) lines are stored in the disk memory 34 saved. In step 82 it is possible to successively generate signals which denote the density of the sections LM and RS and were used in the transverse density correction to erase from memory 34 during this Correction continues.

In step 84- data are sequentially related to read out the longitudinally and transversely corrected density for k (200) lines from the disk memory 34. The selected ones Data is going through to disk storage 4-0 inscribed in the computer, creating the second engraving of the main pattern of the LM section on the impression cylinder 50 takes place. When the engraving is finished, the operation returns to step 72. At this point it will the reading head 20 is placed on the M side of the original 1. Later, the operation is repeated up to step 77 for scanning of the MR section and for engraving of the pattern of the section MR on the printing cylinder 50.

When the engraving of the pattern is finished up to the right side R of the original (i.e., when the second engraving of a main pattern is finished), the operation goes from step 77 to step 81. Then, the operation jumps from step 81 to step 84-. In step 84, data read out with respect to the longitudinally and transversely corrected density of the section LM from the disk memory 34, whereby the cylinder production is carried out for k (200) lines.

Later, the above-mentioned operation (engraving of the pattern of the MR section by scanning and engraving the pattern of the LM section by reading out data of the LM section from disk storage 34) is repeated as many times as necessary, thereby enabling the engraving of endless and multiple patterns is terminated.

In step 90 of sub-program 90, an input identification signal supplied by the HELIO device is checked. In step 93, information is stored in a data memory Da. In step 94, information is retrieved from the data memory Dc to the core memory 4-0. Then, the operation goes to step 95. The above cycle of operation is repeated so that N previous data of each line relating to the density of the section FB is stored in the data memory Da and further N data relating to the corrected density of the section FB from the data memory Dc to the core memory 40 can be retrieved. In the subsequent step 96 , an operation cycle from step 96 to step 99 is repeated η times (200 times) so that η data corresponding to the BC section elongated for longitudinal density correction is stored in a data memory Db, and further η data from the Data memory Dc to core memory 40 can be accessed.

The above explanation relates to an electronic cylinder manufacturing method. However, it is too note that the illustrated embodiment is not a limitation. The invention is self-evident with various changes and modifications feasible.

An auxiliary pattern has been explained above, which additionally extends from the rear end of an original in order to e.g. B. to carry out a longitudinal density correction. However, such an auxiliary pattern can also be used from the front end of the original go out. Furthermore, an auxiliary pattern, which starts from the right end of the original for a lateral density correction, can be starting from the left end of the original. The width of this extended auxiliary pattern was chosen to be approx. 3 cm. However, this width can be larger or smaller.

The numbers η and k were given as 200 each, however, they can be changed. The density correction equations do not need the first and second Group to be limited. The illustrated embodiment relates to a case in which, in addition, for the HELIO device a density correction computer is provided, but the invention is also applicable to other types of electronic cylinder manufacturing facilities applicable. It is also possible to redesign a Electronic cylinder manufacturing machine with the possibility of longitudinal and / or transverse density correction to be provided. A large capacity memory such as a disk memory 3 ^ f is very expensive. Therefore, if z. B. two reading heads are provided to simultaneously scan the sections LM and RS, a longitudinal density correction is performed also without disk storage 3 * f · enabled. if Furthermore, a large capacity memory can be produced inexpensively, it is possible to use an electronic one Processing facility with simplified software and To provide construction by storing all the data of FIGS. 2 and 3 in such a memory will. Also, it is unnecessary to both read data and process a single one To have the device carried out. It is possible to use density data e.g. B. to store on a magnetic tape and to provide separate facilities for reading and processing data.

A cylinder manufacturing facility constructed as described above offers the following significant ones Advantages. In the conventional device, it often happens that when subtle differences in density occur between the leading end and the trailing end of an original and between the right and left end portions the same process error is only discovered

after a test print has been carried out. In such a case, it is very time consuming and costly _y is an original or a vertigert impression cylinder to correct or be prepared again the original. However, with the cylinder manufacturing method given here, the difficulties encountered in the conventional method can be eliminated. Since an original is made by photographing endless and multiple patterns e.g. B. is made in the grain of wood or marble slabs, the front end not directly adjoining the rear end and the patterns are rearranged so that patterns with substantially the same density appearing on the front and back of the original as well as on whose right and left sides are provided to be adjacent to each other, it is difficult to form an original whose leading end and trailing end portions have the same density and whose right and left sides have the same pattern. With the cylinder making method of the present invention, however, differences between the densities of the seams appearing on a printed web can be made less visible, even if the density differences are relatively visible on an original. Thus, the specified cylinder manufacturing method greatly improves the conditions for providing an original.

The known method has the disadvantages that in the event of expansion or contraction of a Originals due to changes in the ambient temperature and humidity as well as the mechanical stress with which a Original is stretched on the outer surface of a printing cylinder, the front and rear end portion of adjacent Pattern as well as the right and left end portions in relation

are shifted slightly on each other, resulting in the appearance of stripes at the junctions between the respective patterns results. The new method, however, eliminates those encountered in the prior art Trouble.

The electronic cylinder manufacturing device according to the invention is manufactured in that the known Facility is provided with a computer. Thus the new device is less expensive than the conventional one Furnishings. Only one original needs to be provided that, compared to the original, for the known method carries a slightly elongated pattern. Thus, in terms of the cost of the new Cylinder manufacturing facility no significant increase over the known facility.

Claims (1)

Claims 1./Electronic cylinder manufacturing process for No endless and / or a multiple pattern, characterized by the following process steps: - Scanning an original on which a main pattern is printed, which is extended to the desired extent at a continuation section, for generating a density signal; - Analog-digital conversion of the density signal for generation of digital information regarding the density of the original; - Correcting the generated digital density information by gradually converting information about the Density of the elongated cough in information about the density of the elongated cough section opposite swatch; and - Engraving a grid pattern on the outside surface of a Printing cylinder in accordance with the contents of a signal indicative of the corrected density. 2. The method according to claim 1, characterized, that one on the extreme left side of the printing cylinder engraved grid pattern from density information, which is in Transverse direction is not corrected, is derived. 3123649 -z- 3. The method according to claim 1 or 2, characterized in that that information on the transverse corrected density is stored in a memory; and that a pattern of that portion of the original whose density is corrected in the transverse direction on the outer surface of the printing cylinder in accordance with the contents of the information about the cross-corrected Density read from memory is engraved ή ·. Electronic cylinder manufacturing device in which an original is scanned to generate a density signal, the density signal is converted into a digital signal to generate digital density information and a raster pattern is engraved on a printing cylinder in accordance with the contents of the digital density information,
marked by a scanning stage for reading out information on the density of an elongated pattern section and a main pattern (3) of the original (1); and a computer recording the density of the swatch opposite the elongated swatch indicative signal in accordance with the contents of the information on the density of the elongated pattern section corrected. 5. Device according to claim ^ t-,
characterized, that the computer provides information on the density of the elongated swatch for the respective scan lines gradually into information about the density of the swatch opposite the elongated swatch implements. 6. Device according to claim 4,
characterized, that the computer has information about the density of the in The transverse direction of the elongated cough section gradually gives information about the density of the that in the transverse direction extended sample section opposite »sample section. 7. Device according to claim k,
characterized, that the computer information about the density of elongated pattern sections gradually into information about the Density of these opposing pattern sections implemented both in the longitudinal and in the transverse direction. 8. Electronic cylinder manufacturing facility for an endless and / or a multiple pattern, characterized by - a reading cylinder (11) and a reading head (20) for scanning an original (1) so that a density signal can be generated; - An analog-to-digital converter (21) which converts the density signal into a digital signal; - A computer that carries out the longitudinal and / or transverse correction of the density information by adding information about the density of an elongated swatch gradually into information about the density of this opposite swatch is implemented; - A digital-to-analog converter (4-2), the information converts the density corrected by the computer into an analog signal; and - An engraving head (43), which is in the outer surface of a Printing cylinder (50) a grid pattern according to the Contents of a supplied from the digital-to-analog converter (42) Density signal engraved. 9. Device according to claim 8, characterized by a memory provided in the computer, the information on the density of a pattern of a portion elongated in the transverse direction of the original (1) saves. 10. Electronic cylinder manufacturing facility for an endless and / or a multiple pattern, characterized by - A unit (20) for scanning the original (1) for the purpose of generating a light signal; - A unit (21) for converting a density signal into a digital signal; - a computer that does the longitudinal and / or lateral correction of the digital density signal and an output signal that denotes the corrected density, provides synchronous with the application of an input signal; - a unit (42) for converting a computer-supplied indicative of the corrected density Signal to analog signal; and - a unit (43) which is mounted on a pressure cylinder (50) engraves a raster pattern in accordance with the contents of a density signal converted into an analog signal. 11. Device according to claim 10, characterized in that - That the original (1) has an endless pattern with a length of approx. 3 cm, which is continuous in the longitudinal direction is given, and / or a multiple pattern with a length of approx. 3 cm, which is spaced in the transverse direction extends, has. 12. Device according to claim 10, characterized in that that the pressure cylinder (50) is engraved with a pattern is, the respective seams of which have a density which is elongated by gradually converting the density of the Pattern section of the original (1) in the density of the opposite pattern section is feasible.